Added server classes, and various robustness hacks

Demo/rpc/rpc.py

@@ -75,6 +75,11 @@ class Packer(xdr.Packer):
 		# Caller must add procedure-specific part of reply
 
 
+# Exceptions
+BadRPCFormat = 'rpc.BadRPCFormat'
+BadRPCVersion = 'rpc.BadRPCVersion'
+GarbageArgs = 'rpc.GarbageArgs'
+
 class Unpacker(xdr.Unpacker):
 
 	def unpack_auth(self):
@@ -82,6 +87,22 @@ class Unpacker(xdr.Unpacker):
 		stuff = self.unpack_opaque()
 		return (flavor, stuff)
 
+	def unpack_callheader(self):
+		xid = self.unpack_uint(xid)
+		temp = self.unpack_enum()
+		if temp <> CALL:
+			raise BadRPCFormat, 'no CALL but ' + `temp`
+		temp = self.unpack_uint()
+		if temp <> RPCVERSION:
+			raise BadRPCVerspion, 'bad RPC version ' + `temp`
+		prog = self.unpack_uint()
+		vers = self.unpack_uint()
+		proc = self.unpack_uint()
+		cred = self.unpack_auth()
+		verf = self.unpack_auth()
+		return xid, prog, vers, proc, cred, verf
+		# Caller must add procedure-specific part of call
+
 	def unpack_replyheader(self):
 		xid = self.unpack_uint()
 		mtype = self.unpack_enum()
@@ -105,11 +126,17 @@ class Unpacker(xdr.Unpacker):
 			  'Neither MSG_DENIED nor MSG_ACCEPTED: ' + `stat`
 		verf = self.unpack_auth()
 		stat = self.unpack_enum()
+		if stat == PROG_UNAVAIL:
+			raise RuntimeError, 'call failed: PROG_UNAVAIL'
 		if stat == PROG_MISMATCH:
 			low = self.unpack_uint()
 			high = self.unpack_uint()
 			raise RuntimeError, \
 				'call failed: PROG_MISMATCH: ' + `low, high`
+		if stat == PROC_UNAVAIL:
+			raise RuntimeError, 'call failed: PROC_UNAVAIL'
+		if stat == GARBAGE_ARGS:
+			raise RuntimeError, 'call failed: GARBAGE_ARGS'
 		if stat <> SUCCESS:
 			raise RuntimeError, 'call failed: ' + `stat`
 		return xid, verf
@@ -193,6 +220,8 @@ def sendrecord(sock, record):
 
 def recvfrag(sock):
 	header = sock.recv(4)
+	if len(header) < 4:
+		raise EOFError
 	x = long(ord(header[0]))<<24 | ord(header[1])<<16 | \
 	    ord(header[2])<<8 | ord(header[3])
 	last = ((x & 0x80000000) != 0)
@@ -359,6 +388,22 @@ class PartialPortMapperClient:
 		self.packer = PortMapperPacker().init()
 		self.unpacker = PortMapperUnpacker().init('')
 
+	def Set(self, mapping):
+		self.start_call(PMAPPROC_SET)
+		self.packer.pack_mapping(mapping)
+		self.do_call()
+		res = self.unpacker.unpack_uint()
+		self.end_call()
+		return res
+
+	def Unset(self, mapping):
+		self.start_call(PMAPPROC_UNSET)
+		self.packer.pack_mapping(mapping)
+		self.do_call()
+		res = self.unpacker.unpack_uint()
+		self.end_call()
+		return res
+
 	def Getport(self, mapping):
 		self.start_call(PMAPPROC_GETPORT)
 		self.packer.pack_mapping(mapping)
@@ -394,6 +439,8 @@ class TCPClient(RawTCPClient):
 	def init(self, host, prog, vers):
 		pmap = TCPPortMapperClient().init(host)
 		port = pmap.Getport((prog, vers, IPPROTO_TCP, 0))
+		if port == 0:
+			raise RuntimeError, 'program not registered'
 		pmap.close()
 		return RawTCPClient.init(self, host, prog, vers, port)
 
@@ -407,6 +454,156 @@ class UDPClient(RawUDPClient):
 		return RawUDPClient.init(self, host, prog, vers, port)
 
 
+# Server classes
+
+class Server:
+
+	def init(self, host, prog, vers, port, type):
+		self.host = host # Should normally be '' for default interface
+		self.prog = prog
+		self.vers = vers
+		self.port = port # Should normally be 0 for random port
+		self.type = type # SOCK_STREAM or SOCK_DGRAM
+		self.sock = socket.socket(socket.AF_INET, type)
+		self.sock.bind((host, port))
+		self.host, self.port = self.sock.getsockname()
+		self.addpackers()
+		return self
+
+	def register(self):
+		if self.type == socket.SOCK_STREAM:
+			type = IPPROTO_TCP
+		elif self.type == socket.SOCK_DGRAM:
+			type = IPPROTO_UDP
+		else:
+			raise ValueError, 'unknown protocol type'
+		mapping = self.prog, self.vers, type, self.port
+		p = TCPPortMapperClient().init(self.host)
+		if not p.Set(mapping):
+			raise RuntimeError, 'register failed'
+
+	def unregister(self):
+		if self.type == socket.SOCK_STREAM:
+			type = IPPROTO_TCP
+		elif self.type == socket.SOCK_DGRAM:
+			type = IPPROTO_UDP
+		else:
+			raise ValueError, 'unknown protocol type'
+		mapping = self.prog, self.vers, type, self.port
+		p = TCPPortMapperClient().init(self.host)
+		if not p.Unset(mapping):
+			raise RuntimeError, 'unregister failed'
+
+	def handle(self, call):
+		# Don't use unpack_header but parse the header piecewise
+		# XXX I have no idea if I am using the right error responses!
+		self.unpacker.reset(call)
+		self.packer.reset()
+		xid = self.unpacker.unpack_uint()
+		self.packer.pack_uint(xid)
+		temp = self.unpacker.unpack_enum()
+		if temp <> CALL:
+			return None # Not worthy of a reply
+		self.packer.pack_uint(REPLY)
+		temp = self.unpacker.unpack_uint()
+		if temp <> RPCVERSION:
+			self.packer.pack_uint(MSG_DENIED)
+			self.packer.pack_uint(RPC_MISMATCH)
+			self.packer.pack_uint(RPCVERSION)
+			self.packer.pack_uint(RPCVERSION)
+			return self.packer.get_buf()
+		self.packer.pack_uint(MSG_ACCEPTED)
+		self.packer.pack_auth((AUTH_NULL, make_auth_null()))
+		prog = self.unpacker.unpack_uint()
+		if prog <> self.prog:
+			self.packer.pack_uint(PROG_UNAVAIL)
+			return self.packer.get_buf()
+		vers = self.unpacker.unpack_uint()
+		if vers <> self.vers:
+			self.packer.pack_uint(PROG_MISMATCH)
+			self.packer.pack_uint(self.vers)
+			self.packer.pack_uint(self.vers)
+			return self.packer.get_buf()
+		proc = self.unpacker.unpack_uint()
+		methname = 'handle_' + `proc`
+		try:
+			meth = getattr(self, methname)
+		except AttributeError:
+			self.packer.pack_uint(PROC_UNAVAIL)
+			return self.packer.get_buf()
+		cred = self.unpacker.unpack_auth()
+		verf = self.unpacker.unpack_auth()
+		try:
+			meth() # Unpack args, call turn_around(), pack reply
+		except (EOFError, GarbageArgs):
+			# Too few or too many arguments
+			self.packer.reset()
+			self.packer.pack_uint(xid)
+			self.packer.pack_uint(REPLY)
+			self.packer.pack_uint(MSG_ACCEPTED)
+			self.packer.pack_auth((AUTH_NULL, make_auth_null()))
+			self.packer.pack_uint(GARBAGE_ARGS)
+		return self.packer.get_buf()
+
+	def turn_around(self):
+		try:
+			self.unpacker.done()
+		except RuntimeError:
+			raise GarbageArgs
+		self.packer.pack_uint(SUCCESS)
+
+	def handle_0(self): # Handle NULL message
+		self.turn_around()
+
+	# Functions that may be overridden by specific derived classes
+
+	def addpackers(self):
+		self.packer = Packer().init()
+		self.unpacker = Unpacker().init('')
+
+
+class TCPServer(Server):
+
+	def init(self, host, prog, vers, port):
+		return Server.init(self, host, prog, vers, port, \
+			socket.SOCK_STREAM)
+
+	def loop(self):
+		self.sock.listen(0)
+		while 1:
+			self.session(self.sock.accept())
+
+	def session(self, connection):
+		sock, (host, port) = connection
+		while 1:
+			try:
+				call = recvrecord(sock)
+			except EOFError:
+				break
+			reply = self.handle(call)
+			if reply <> None:
+				sendrecord(sock, reply)
+
+
+class UDPServer(Server):
+
+	def init(self, host, prog, vers, port):
+		return Server.init(self, host, prog, vers, port, \
+			socket.SOCK_DGRAM)
+
+	def loop(self):
+		while 1:
+			session()
+
+	def session(self):
+		call, host_port = self.sock.recvfrom(8192)
+		reply = self.handle(call)
+		if reply <> None:
+			self.sock.sendto(reply, host_port)
+
+
+# Simple test program -- dump local portmapper status
+
 def test():
 	import T
 	T.TSTART()
@@ -423,3 +620,50 @@ def test():
 		elif prot == IPPROTO_UDP: print 'udp',
 		else: print prot,
 		print port
+
+
+# Server and client test program.
+# On machine A: python -c 'import rpc; rpc.testsvr()'
+# On machine B: python -c 'import rpc; rpc.testclt()' A
+# (A may be == B)
+
+def testsvr():
+	# Simple test class -- proc 1 doubles its string argument as reply
+	class S(TCPServer):
+		def handle_1(self):
+			arg = self.unpacker.unpack_string()
+			self.turn_around()
+			print 'RPC function 1 called, arg', `arg`
+			self.packer.pack_string(arg + arg)
+	#
+	s = S().init('', 0x20000000, 1, 0)
+	try:
+		s.unregister()
+	except RuntimeError, msg:
+		print 'RuntimeError:', msg, '(ignored)'
+	s.register()
+	print 'Service started...'
+	try:
+		s.loop()
+	finally:
+		s.unregister()
+		print 'Service interrupted.'
+
+
+def testclt():
+	import sys
+	if sys.argv[1:]: host = sys.argv[1]
+	else: host = ''
+	# Client for above server
+	class C(TCPClient):
+		def call_1(self, arg):
+			self.start_call(1)
+			self.packer.pack_string(arg)
+			self.do_call()
+			reply = self.unpacker.unpack_string()
+			self.end_call()
+			return reply
+	c = C().init(host, 0x20000000, 1)
+	print 'making call...'
+	reply = c.call_1('hello, world, ')
+	print 'call returned', `reply`